The present invention relates to a lamp for motor vehicles including a fog warning or backup lamp. With regard to fog warning or backup lamps it is important that for achieving the necessary light values the light from a bulb projecting into a lamp compartment is optimumly utilized. Therefore known fog warning and backup lamps include a parabolic reflector at the back of the lamp compartment, which parabolic reflector diverts the light which is directed to the side as well as that which is partially directed backwardly to a transparent cover glass at the front of the lamp compartment. Thus, not only the rays directly cast onto the cover glass by the bulb but also the indirectly cast rays pass out through the cover glass.
In certain applications the surface through which light from the lamp compartment passes outside must be kept relatively small. The manufacturer of motor vehicles may require this for reasons of design. In lamps for motor vehicles with several compartments, in which lamps a plurality of functions, including, for example, a fog warning lamp, a backup lamp, a turn-signal lamp and rear and stop lamp is combined, the light transmitting surface of the fog warning or backup lamp, is provided at a predetermined distance of the light transmitting surfaces assigned to the other functions so that when the fog warning or the backup lamp is switched on, a signal passing an adjacent light transmitting surface is still clearly distinguishable. Thus, at the front of the lamp for motor vehicles there is a portion that cannot be used for the transmission of light, and the lamp for motor vehicles cannot exceed a certain size. This then results in a small light transmitting surface for a particular signalling function.
It is therefore an object of the present invention to develop a lamp for motor vehicles with the noted features such that even with a small light transmitting surface, the necessary light values are nevertheless achieved.